Abstract: A system for sequentially refreshing segments of the stored voltage characteristics of electron guns includes a clock gate. The clock gate passes clock pulses to a counter which refreshes the stored voltage signals. After a predetermined number of counts, the counter inhibits the clock gate until a vertical blank pulse enables the clock gate and the counter resumes counting.

Abstract: The minimum output level of an electron gun driven at discrete voltage levels is precisely established. A target value slightly above the minimum voltage level is compared with the actual value. The result of the comparison is used to uniformily establish the minimum electron gun drive voltage and thus compensates for electron gun transfer characteristic differences and variations within the gun drive circuitry. An additional circuit utilizing a target value slightly below the maximum voltage can be used to establish the maximum output level of the electron gun.

Abstract: The analog video signal for a modular flat panel display device is digitized in an analog to digital converter. The digitized data are supplied to a left/right serial shift register. A left/right control signal causes the left/right shift register to periodically receive data on either a left input terminal during a left loading mode or a right input terminal during a right loading mode. In each loading mode a portion of the data are output from the serial register over a right output terminal and the other portion over a left output terminal. Accordingly, during each loading mode one portion of the data is output in the same order as received and the other portion in an order reversed from the received order. The data from the left/right register are supplied to primary registers and because of the operation of the left/right register data for adjacent primary registers are in opposite order.